Carbureter.



G. A. F. AHLBERG.

CARBURETER.

APPLICATION FILED NOV 28,19). 1,138,829. Patented May 11, 1915.

GUSTAV A. F. AHLBERG, OF CHICAGO, ILLINOIS.

CARBURETER.

Specification of Letters Patent.

Patented May 11, 1915.

Application filed November 28, 1910. Serial No. 594,521.

To all whom it may concern:

Be it known that I, GUSTAV A. F. AHL- mzno, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Carbureters, of which the following is a description, reference being had to the accompanying drawings, forming a part of this specification, in which corresponding numerals of reference in the different figures indicate like parts.

My invention relates to carbureters intended for use in conjunction with internal combustion engines of the four cycle type, and the primary object of my invention is to utilize simple means, for varying the quantity of air which may be admitted directly from the atmosphere to the combustion chamber, to vary the vacuum of the latter in relative conformity to the variations in load and speed of the engine, so that the suction caused by the main piston upon its suction stroke, modified by the varying quantity of air thus drawn into said chamber, may, in turn, be utilized to regulate the quantity of liquid fuel drawn into the mixing chamber. In other words, it is my purpose to provide means for producin a primary mixture of liquid fuel and air of excessive richness in a primary mixing chamber and then causing said rich mixture to be remixed with the requisite quantity of atmospheric air in a secondary mixing chamber before being introduced to the combustion chamber, thereby insuring a thorough, complete and uniform mixture of the combustion charge while maintaining its quality and varying its quantity in accurate conformity to variations in load and speed. In view of these objects, my invention consists in the combination of elements hereinafter set forth and particularly claimed.

In the drawings, Figure 1, is a plan view of a carbureter and a portion of the cylinder of an internal combustion engine, the former being shown in horizontal section taken upon the line 1, Fig. 2; Fig. 2, is a vertical sectional view taken upon the line 2, Fig. 1, viewed in the direction of the arrow there shown, and Fig. 3 is an end view of the ca'burcter showing the adjustable slide-valve therein.

Referring to the drawings, 1 represents the main cylinder of an internal combustion engine of the four-cycle type having an induction opening 2, for the passage of the fuel charge which is adapted to be closed by means of an inwardly opening valve 3, the stem 4 of which is mounted in a hearing within a casing 5, while a light spring 6, tends to close it. The casing 5 is, by preference, substantially elbow-shaped as shown and is open at the end as indicated at 7, so as to form a conduit or chamber 8 in communication with the atmosphere and combustion chamber respectively.

Mounted upon a bracket or support 9, which, in the example shown, is made integral with the caslng 5, is a carbureter, generally designated by 10 having a mixing chamber 11. A tapered nozzle 12, preferably circular in cross-section is formed upon one end of the mixing chamber, the opening in which forms the discharge from said chamber. Said discharge nozzle is projected through the opening 7 into the chamber 8 which is intended to form not only an air passage, but likewise a secondary mixing chamber for the purpose hereinafter described. Located within said chamber isa butterfly valve 13, the shaft or pivot of which is extended through the casing and is rigidly attached to an arm 14, by which said valve may be moved in any approved way; it being understood that the purpose of said valve is to control the quantity of fluid mixture to be introduced to the engine cylinder, by restricting the area of the passage thereto, which restriction serves to form a partial vacuumof varying degree, according to the relative position of the valve, between said valve and the engine piston the importance and significance of which will be hereinafter stated. In order to enable the air opening 7, to be adjusted to provide for the admission of the requisite volume of air needed for the maximum load, an adjusting ring 15 is fitted with n the casing 5 around the nozzle 12. Said ring is held in place by means of plus 16 projected through slots 17, in the casing and provided with adjusting nuts 18. The opening in said ring is tapered as shown to conform to the taper 0f the nozzle and the movement of the ring forward or back,

serves to vary the annular space between I the two to any desired extent.

The mixing chamber 11 is provided with an induction air opening 19. A slide valve 20 having a corresponding opening therein is intended to have a fixed adjustment adapted to admit a predetermined quantity of air and when once adjusted, may be secured by means of a thumb-screw 21.

The carbureter casing is provided with a horizontal partition 22 by which it is divided from the fuel chambers 23, 24, separated from each other by means of a transverse vertical partition 25. Within the chambers 23 and 24 respectively are located valve casings 26 and 27 which extend from the partition 22 above the top of the casing and are provided with screw-caps 28, having air openings 28 therein. Said casings are bored to form cylindrical chambers and in each is fitted a tapered plug 29 by which each of said chambers is divided into upper and lower compartments. The caps 28 and plugs 29 are centrally bored for the reception of the stems 30 and 31 of needle valves 32 and 33 located within the casings 26 and 27 respectively. Pistons 34, 35 are located in piston chambers 36, 37. Light springs 38 are interposed between the screw caps 28 and washers 39 the latter of which held in place by means of adjusting nuts 40, serve to hold the valves normally open. A small chamber 41, is located between the casings 26 and 27 and is in communication With the piston-chambers beneath the pistons, by means of ports 42. A pipe 43 serves to connect chamber '41 with the lower portion of the chamber or conduit within the casing 5 as shown at 44, Fig. 2. The chambers 23 and 24 are divided by means of low transverse partitions 45, 46 res ectively, thereby forming compartments 4 and 48 in the chamber 23, and 49 and 50 in the chamber 24. The compartment 47 is in communication by means of a pipe 51, with a source of water supply, not shown, while a return pipe 52, is connected with the compartment 48, thereby enabling a supply of water to be maintained at a constant level in the compartment 47. Like supply and return pipes 53, and 54 serve to connect the compartments 49 and 50 with a source of hydrocarbon oil supply in the same manner. The chamber 23 is in communication through ports 55, with a valve chamber 56, which is provided with a valve or feed opening 57, leading to the mixing chamber, while the chamber 24 is in communication in like manner through ports 58, with a vali e chamber 59, having a feed opening 60 also leading to said mixing chamber.

The operation of the, device described is as follows :Assuming the ring 15 and the slide-valve 20 to be adjusted in a predetermined relation to each other to enable the air and fuel to be mixed in proper proportion for all loads and to admit a sufficient quantity of air for a maximum load, the piston, upon its suction stroke serves to open the valve 3 and to draw in air through the opening 7 and around the nozzle 12, at a high velocity, thereby acting as an inector to induce a flow from the mixing chamber 11. \Vith a full load and correspondingly reduced speed, the lever 14 should be moved to open the valve 13 to its full limit. This adjustment of the valve permits a maximum quantity of air to enter the pipe 5, or secondary mixing chamber from where it passes to the engine cylinder, which passage, in turn, serves to induce a flow of air and fuel from the primary mixing chamber, thereby causing a maximum degree of vacuum in the latter. The relative vacuum in the secondary mixing chamber formed between the regulating valve and the engine piston, is however, reduced to a minimum. This minimum vacuum, the degree of which is governed by the extent to which the fluid passage is restricted by the regulating "alve, is communicated through the pipe 43, to the chamber 41 and thence, through the openings 42, to the space beneath the pistons 34 and 35 respectively, thereby offering a minimum resistance to the action of the springs 38, which are free to open the valves 32 and 33 to nearly their full limit. The relatively high vacuum produced in the primary mixing chamber causes a suction through the openings 57 and 60 and 55 and 58, thereby producing a corresponding vacuum in the chambers 23 and 24. The water in the chamber 47, and the oil in the chamber 40, is maintained at a constant level as stated, so that the suction caused by the vacuum in the primary mixing chamber may cause a flow of liquid through the openings 58, with each pulsation; the quantity being proportionate to the degree of suction.

It follows from what has been stated, that when the maximum quantity of air is admitted to the secondary mixing chamber, a maximum degree of vacuum will have been formed in the primary mixing chamber and hence a maximum flow of fuel thereto will have resulted. The valve 20 should be set so that whatever the suction, the relative quantity of air admitted through the opening 19 will serve to produce a gas of excessive richness in the primary mixing chamber. It will be noted that not only do separate mixing actions occur in the primary and secondary mixing chambers but the passage of this remixed charge around the valve 3 serves to again cause a thorough commingling action in the engine cylinder which, in

maintained so as to insure complete combustion at all times.

It is obvious that the valve 3 may be opened by positive mechanical means and that other variations in the structure may be made without departing from the principle involved in the invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is: i

1. A carbureter, comprising in combination primary and secondary chambers, each having an air inlet and a discharge outlet, the discharge outlet of said primary chamber leading into said secondary chamber, whereby a fiow from the former may be induced b a suction through the latter, a source 0 fuel supply in communication with an opening leading to said primary chamber, a fuel valve for varying the effectiveness of said opening, yielding means tending to hold said valve fully open, a vacuum controlled piston arranged to oppose said yielding means, a fuel mixture regulating valve within and near the entrance to said secondary chamber, means for controlling the same from without, and a conduit leading from a oint in advance of said fuel mixture regulating valve to the chamber of said vacuum controlled piston, to enable the variation in vacuum at said point to be communicated to said piston chamber to vary the effective opening of the fuel valve.

2. A carbureter, comprising in combination primary and secondary chambers, and having an air inlet and a discharge outlet, the discharge outlet of said primary chamber leading into an inlet to said secondary chamber with a space between open to the atmosphere, a source of fuel supply in communication with said primary chamber, a fuel valve for varying the effective fuel opening, yielding means tending to hold said valve fully open, a vacuum controlled piston arranged to oppose said opening means, a fuel mixture regulating valve within and near the entrance to said secondary chamber, means for actuating said valve from without, and a conduit leading from a point located between the discharge opening of said secondary chamber and said fuel mixture regulating valve to the piston chamber of said vacuum controlled piston.

3. A carbureter, comprising in combination primary and secondary chambers each having an air inlet and a discharge outlet, the discharge outlet of said primary chamber leading into the open end of said secondary chamber with a space between the two open to the atmosphere, means for varying the effective air opening leading to said primary chamber, a source of fuel supply in communication with said primary chamber, a fuel valve for varying the fuel supply opening, yielding means for holding said valve normally open, a vacuum controlled piston arranged to oppose said opening means, a fuel mixture regulating valve within and near the entrance to said secondary chamber, means for actuating said valve from without to vary the quantity of fluid admitted thereto and a conduit leading from a point between said fuel mixture regulating valve and the discharge opening of said secondary chamber to the piston chamber of said vacuum controlled piston.

45. A carbureter, comprising in combination primary and secondary chambers, each having an air inlet-and a discharge outlet, the discharge outlet of said primary chamber leading into the open end of said secondary chamber with a space between the two open to the atmosphere, means for varying the effective area of the air opening leading to said secondary chamber, a source of fuel supply in communication with said primary chamber, a fuel valve for varying the fuel supply opening, yielding means for holding said valve normally open, a vacuum controlled piston arranged to oppose said opening means, a fuel mixture regulating valve within and near the entrance to said secondary chamber, means for actuating said valve from without to vary the quantity of fluid admitted thereto and a conduit leading from a point between said fuel mixture regulating valve and the discharge opening of said secondary chamber to the piston chamber of said vacuum controlled piston.

5. A carbureter, comprising in combination primary and secondary chambers, each having an air inlet and a discharge outlet, the discharge outlet of said primary chamber leading into the open end of said secondary chamber with a space between the two open to the atmosphere, means for varying the effective area of the air opening leading to each of said chambers, a source of fuel supply in communication with said primary chamber, a fuel valve for varying the fuel supply opening, yielding means for holding said valve normally open, a vacuum controlled piston arranged to oppose said opening means, a fuel mixture regulating valve within and near the entrance to said secondary chamber, means for actuating said valve from without the chamber to vary the volume of fluid admitted thereto and a conduit in communication with said secondary chamber in advance of said fuel mixture regulating valve, said conduit leading to the piston chamber of said vacuum controlled piston.

6. A carbureter, comprising primary and secondary mixing chambers each having an air inlet and a mixture discharge outlet, the outlet ofsaid primary chamber leading to said secondary chamber and that of said secondary chamber to the engine cylinder, a source of fuel supply in communicationwith said primary chamber, a fuel valve for varying the fuel supply opening, yielding means for holding said valve in a predetermined position, a vacuum controlled piston arranged to oppose the normal tendency of said yielding means, a butterfly valve located within and near to the entrance of said secondary chamber for varyingthe volume of fluid admitted thereto, means for actuating said valve without the chamber and a conduit in communication With said secondary chamber in advance of said butterfly valve, said conduit leading to the pis ton chambers of said vacuum controlled piston.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses, this 25th day of November, 1910.

GUSTAV A. F. AHLBERG.

Witnesses:

DAVID H. FLETCHER, JENNIE L. FIsKE. 

